Note: Unless you are using a severely outdated operating system or CPU, you most likely want to always download the x64 (64-bit) version of Ultimate Doom Builder.
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
All recent versions
Ultimate Doom Builder R4251
02 Nov 2025
Fixed an issue where showing any system dialog from within Visual Mode would result in UDB being unresponsive to keyboard input. Fixes #1152
Ultimate Doom Builder R4250
01 Nov 2025
Fixed an issue where, when using a grid size smaller than 1, things would snap back to non-fractional grid positions after dragging. Fixes #1160
Ultimate Doom Builder R4249
01 Nov 2025
Fixed an issue where ambient sound things 1-64 did not show their range circles. Fixes #1173
Ultimate Doom Builder R4248
25 Oct 2025
Fixed an issue where polyobjects were erroneously reported to have no polyobject start spot of any kind the the Eternity Engine game configuration. Fixes #1221
Ultimate Doom Builder R4242
20 Sep 2025
Script Editor: fixed a crash when the script contains malformed named script definitions. Fixes #1239